Convertible boat hull



R. G. MATURI ETAL 3,129,443

CONVERTIBLE BOAT HULL April 21, 1964 Filed Jan. 10, 1961 v 2Sheets-Sheet 1 April 21, 1964 R. G. MATURI ETAL 3,129,443

CONVERTIBLE BOAT HULL Filed Jan. 10, 1961 2 Sheets-Sheet 2 United StatesPatent ()fiice 3,129,443 Patented Apr. 21, 1964 3,129,443 CGNVERTIBLEBGAT HULL Rodolphe Gerard Maturi, 136 Rue Lamar-ch, Paris 18,

France, and Qhris'tian Eelietti, 15 Rue du Val de Grace,

Paris 5, France Fiied 32m. 1a, 1961, Still. No. sues Claims priority,application France Tan. 12, 1960 4 Claims. (61. 9-2) The water lines ofan outboard motor boat hull and the hull of a sailing boat indisplacement are differently shaped, and up till now, the constructionof a single hull giving good hydrodynamic results in each of theseutilizations: either an outboard motor boat or sailing boat, wasconsidered impossible or at least unrealizable, more particularly if itwas desired to obtain a lower cost price thzm that of two hullsspecially devised for outboard motor boat and sailing boat purposes.

The present invention enables this problem to be solved, by creating amain element of a hull capable of being associatedor notwith auxiliaryelements for forming an outboard motor boat hull or to cooperate withthird elements for forming a sailing boat hull, this principal elementbeing subjected to additional loads, in particular to the weight of thepassengers, to the weight of the engine and to stresses due to the windexerted on the sail, etc., whose application point and direction can bedisplaced so that the water lines conform with those for working as anoutboard motor boat or sailing boat for which the hull is loaded andarranged.

According to the invention, the convertible boat hull comprises a mainelement able to be associated, eventually, with at least one auxiliaryelement for forming the hull of an outboard motor boat and cooperatingwith third elements for forming a sailing boat hull, all these elementsbeing shaped and the distribution of static and dynamic loads to whichthey are subjected when running, being varied in such a manner that theresults obtained from the outboard motor boat hull and the sailing boathull thus obtained are considerable.

Various other characteristics will moreover be revealed by the detaileddescription which follows.

Forms of embodiment of the purpose of the invention are shown, by way ofexamples, in the attached drawing.

FIGURES l and 2 are longitudinal sectional elevations of elementsforming a first form of embodiment of the hull according to theinvention.

FEGURES 3 and 4 are plan views of these elements seen whose half isshown in section along the lines 111-- III and IV-IV of FIGURES 1 and 2respectively.

FIGURE 5 is a diagrammatic elevational view showing a second form ofembodiment of the hull.

FIGURES 6 and 7 are diagrammatic elevations showing a third form ofembodiment of the hull showing two possibilities of mounting itscomponent elements.

FIGURES 8 and 10 are elevational views showing a hull in twocharacteristic working positions.

FIGURES 9 and 11 are plan views of the hull, diagrammatized in FIGURES 8and 10, on which the water lines are shown characterizing the two typesof working.

According to a first form of embodiment shown in FZGURES 1 to 4, thehull comprises a main element 1 s0 shaped as to ensure good hydrodynamicresults when used independently for acting as an outboard motor boat.This main element is able to be associated with another element 2,rigidly fixed to the rear of element 1 so as to form, in cooperationwith it, a sailing boat hull whose element 2 represents the front. Theshape of the latter is provided so as not to set up any continuitysolution or any angular surface in the connecting zone of said elements,but also to afford good hydrodynamic results from the hull when theseassociated elements are used as a sailing boat.

According to a second form of embodiment (FIG- URE 5) the hull comprisesa main element 3 of which at least part is shaped so as to afford a goodresult, when this element is used for an outboard motor boat. The rearpart of the latter can be made integral with another element 4, when thehull is to be converted for constructing a sailing boat, whose rear isformed by this element 4. The shape of the ribs of said element 4 andthe front of the element 3 is so devised that, by associating these ribswith that of the remaining part of this element 3, good results can beobtained from the hull for a sailing boat.

According to a third form of embodiment shown in FIGURES 6 and 7, thehull comprises a central element 5 to whose end can be fixed eitherfront and rear elements 6 and 7 to form a sailing boat hull, or a frontelement 3 and a rear element 9 for forming an outboard motor boat hull.The shape of the front elements 6 and 3 and rear elements 7 and 9 isdifferent, so that by using a common central element 5, acceptableresults may be obtained from the hull, whether used as a sailing boatwith the elements 6 and 7 or as an outboard motor boat with the elements8 and 9.

In the examples described above, the outboard motor boat hull or thesailing boat hull are obtained by juxtaposing elements in a longitudinaldirection which totally comprise each couple of the corresponding partof the hull. It is quite obvious that this hull of an outboard motorboat or sailing boat can be obtained by juxtaposing supplementaryelements in a cross direction of which each couple is associated withthe opposite element or elements for forming the corresponding couple ofthe hull, and then, by juxtaposing these elements assembledtransversely, in a longitudinal direction.

The above-mentioned elements 1 to 9 are watertight over their entireperiphery and can even comprise watertight caissons in order to makethem unsinkable. The bottom of these elements, and in particular, theprincipal elements 1, 3 and middle one 5, is flat, but can be slightlycurved in a V, U-shape or hollow. Moreover, there is nothing to preventthis bottom comprising, in certain embodiments, at least one step.Moreover, these elements can be made of all the material usuallyutilized and possibly others, namely: worked-up wood, marine plywood,metal alloys, waterproofed canvas covering a framework, :stratifiedglass fabric and synthetic resins, Watertight inflatable cover, etc.,the construction of said elements putting into etiect all known or newtechnique applied to these materials.

The elements are connected to each other by means of fixing membersmentioned as examples in that which follows. These members can berustless metal alloy bolts, such as brass, threaded rods and nuts,straps, hoops, eccentrics, knockle bolts, quick tightening grips such asthose known under the name of bevels, housings and pins, etc.

The first form of embodiment is shown in FIGURES 1 to 4 and by way ofnon-restrictive example, according to a construction of wood and marineplywood, a construotion type which is generally very popular owing toits low cost price. The main element 1 comprises a stem 10, couples 11and 12 and a rear panel 13 provided with a plate 14 and strengtheningsurround 1 2a which are connected by means of internal strakes 15. Theupper horizontal part of the couple 11 of ring shape forms andinstrument panel 16, whereas the upper horizontal parts of the opencouple l2. sup-port gunwales 17, which eventually, can rest on severalother couples 12. The framework thus formed is covered by a hull flat 18and a deck fiat 19 which, in cooperation with the gunwales 17, form aWorking covering of marine plywood. The internal strakes 15 are alsoutilized as floor battens '2 to on which seats or benches 24 are fixedwhich can be connected to the couples 11 and 12.

The rear panel 13 and its strengthening plate 14 are intended to hold anoutboard motor. The broken lines 211 show the center lines of fasteningmembers, such as those previously described, enabling connection to beeffected between the main element 1 and the third element 2. It will benoticed that the bottom of the hull fiat 18 is extended towards the rearat 22, in order to ensure good stability when running of the mainelement 1 used as an outboard motor boat hull, and that the externalstrakes 23 are attached to the lateral parts of this hull flat. The deckflat 19 can be provided with rapid fixing members for a rudder enablingthe main element 1 to be steered, when the latter is used in cooperationwith the third element 2 as a sailing boat hull. The main element 1 can,moreover, be provided with various other accessories for operating itand propelling it, such as: flywheel and transmission cables, memberscontrolling the motor, hinged supports for cars, etc., and comprisevarious arrangements for passengers comfort.

The third element 2 of this first form of embodiment is shaped like awatertight caisson formed by a stem 24 connected to a rear plate 25 by adouble middle rib 26 surrounding a lower step 27 and a well 25, aworking covering, composed of a deck flat 29 and a hull flat 39 ofplywood pressed into shape, covers the stem, the rib, the lower plateforming a couple and eventually intermediate couples (not shown). Theconnection between this rear plate and the flats is strengthened bymeans of planks and slats 31. 32 denotes the center lines of thecooperating parts of fastening members 21 with which the rear panel 13and the main element 1 are provided.

The Well 28 is delimited by a surround 33 integral with the rear plate25 and connected to the stem 24 by the ribs 26, at the lower part, andby a middle strake 34 at the top part. This well, giving on to the deckflat 29 and hull flat 30, is provided internally with rollers 35 forguiding an incurved centre-board 36 able to be more or less lowered forkeeping the sailing boat keel in line formed by the juxtaposed elements1 and 2. The step 27 and deck flat 29 as Well as the ribs 34 delimitcircular orifices for stepping a mast 37 carrying at least one sail.

Thus, the main element 1 of conventional construction, can be usedindependently as outboard motor boat hull, and in cooperation with thethird element 2, as a sailing boat hull. These two types of bull areprovided with all improvements and necessary accessories forsatisfactory utilization.

It results from the foregoing that the shape of the hull, convertibleaccording to the invention, is an important factor for obtaining goodhydrodynamic results, but FIGURES 8 to 11 show that for improving theseresults, other factors can be introduced. For example, the centre ofgravity of the hull can be shifted from G (FIGURE 8) toward G (FIGURE10) and inversely, by altering the distribution of the loads fixed tothe latter:

addition or removal of a hull element, additional loads such aspassengers both in number and position, the motor, etc. The centre ofdynamic thrust of this hull can also be shifted by altering its shape byadding or removing an element, altering its speed which is necessarilydifferent according to the method of propulsion, sail or motor, etc. Theposition of the water-line 38 in relation to a sailing boat hull 39 whenmoving (FIGURE 8) is different to that of a water-line 46 in relation toan outboard motor boat hull 411 when moving (FIGURE 10). In the firstcase, the water lines 42 of the hull 39 are characteristic of a sailingboat, and in the second case, the water lines 43 of the hull 41 are, onthe other hand, characteristic of an outboard motor boat. Actua1 ly, thelines 42 are closed showing towards the rear a curved shape and towardsthe front a bent shape terminating in a point, whereas the lines 43 areopen.

We claim:

1. A convertible boat hull comprising a plurality of sections, one ofsaid sections forming an end of a sailboat hull, means for releasablyconnecting said sections together to form a sailboat hull and forremoving said one section to form an outboard motor boat hull, and saidsections being shaped for varying the distribution of static and dynamicloads in such a manner that optimum hydrodynamic results are obtainedfrom the outboard motor boat hull and from the sailing boat hull.

2. A convertible boat hull according to claim 1 wherein the other ofsaid sections comprises an integral outboard motor boat hull.

3. A convertible boat hull according to claim 2 wherein the said onesection includes a well for supporting a center board and means forsupporting a mast.

4. A convertible boat hull comprising a plurality of sections forselectively forming a sailboat hull and an outboard motor boat hull,said sections including a center section and a plurality of auxiliarysections, said center section comprising a main hull element having eachof its ends adapted to be connected selectively with said auxiliarysections, said auxiliary sections including a pair of elements shaped toform the front and rear of a sailboat and a pair of elements shaped toform the cEront and rear of an outboard motor boat, and means forreleasably connecting one pair of said elements to i said main hullelement to form the appropriate boat hull.

References Cited in the file of this patent UNITED STATES PATENTS764,473 Kilgore July 5, 1904 2,569,686 Melchoir Oct. 2, 1951 2,741,782Muller Apr. 17, 1956 FOREIGN PATENTS 176,965 Great Britain Mar. 23, 1922407,491 Great Britain Mar. 22, 1934 479,256 Great Britain Feb. 2, 1938967,928 France Apr. 5, 1950

1. A CONVERTIBLE BOAT HULL COMPRISING A PLURALITY OF SECTIONS, ONE OFSAID SECTIONS FORMING AN END OF A SAILBOAT HULL, MEANS FOR RELEASABLYCONNECTING SAID SECTIONS TOGETHER TO FORM A SAILBOAT HULL AND FORREMOVING SAID ONE SECTION TO FORM AN OUTBOARD MOTOR BOAT HULL, AND SAIDSECTIONS BEING SHAPED FOR VARYING THE DISTRIBUTION OF STATIC AND DYNAMICLOADS IN SUCH A MANNER THAT OPTIMUM HYDRODYNAMIC RESULTS ARE OBTAINEDFROM THE OUTBOARD MOTOR BOAT HULL AND FROM THE SAILING BOAT HULL.